Method of forming screw-threads in cylindrical metal articles.



E. R. DOUGLAS, METHOD OF FORMING SCREW THREADS IN CYLINDRIGAL METAL ARTICLES.

APPLICATION FILED 116mm, 1911v 4% vi L 0d T 23 E a E. hv H d n a M E E m H LIU S n 5 .w a P mamms E. R. DOUGLAS. METHOD OF FORMING SCREW THREADS IN GYLINDRICAL METAL ARTICLES.

APPLTI'XATIOH FILED NOV. 27, 1911. 1,083,598.

Patented Jan. 6, 1914.

' 6 SHEETS-SHFET 2.

WITNESSES INVENTOR monmzvs E. R. DDUGLAS. METHOD OF FORMING SCREW THREADS IN CYLINDRIOAL METAL ARTICLES.

Patented Jan. 6, 1914.

APPLICATION FILED NOV 27,1911.

5 SHEBTS-SHBET 3.

fmvsmun moansvs E. R. DOUGLAS.

' METHOD OF FORMING SCREW THREADS IN GYLINDRIOAL METAL ARTICLES.

' APPLICATION FIL'ED NOV. 27, 1911.

1,083,598. Patented Jan. 6, 1914.

5 SHEETS-SHEET 4.

An ina!!! I 1 1 ATTORNEYS B. R. DOUGLAS.- METHOD OF FORMING SCREW THREADS IN GYLINDRIGAL METAL ARTICLES.

v APPLICATION FILED NOV. 27, 1911.

Patented Jan. 6, 1914.

5 SHEETS-SHEET 6.

WITNESSES mvemon ATTORNEYS AYAIL in nnwm nosrnouoras, orennnsihn, rnnnsrnvanmi -METHOD or ronmme sonnw-rnnnans IN .cYL-innnicaL METAL lam st.

Specification of Iletters' latent.

Original application filed Kay '4, 1911, Serial No. 624,979. Divided and this application filed Novemb 27, 1911. swarm. 662,677.

7' Threads in Cylindrical Metal Articles, of

To all whom it may concern: f

Be it known that I, EDWIN Rus'r DOUGLAS, a citizen of the United States, residing in Glenside, in the county of Montgomery, State of Pennsylvania, have invented a new and useful Method of Forming Screw- V which the following is a specification;

My invention consists of an improved method of forming screw-threads in cylindrical metallic articles.

It further consists of such a method in Y which the metal of the article iscrowded or drawn to form a raised screw-thread on one side, only, of the material.

It further consists in exposing the surface A to be threaded to a revolving screw-threaded threaded tool.

tool.

the side of the article which is to remain smooth while exposing the side to be threaded to the action of a revolving screw- It further consists in exposing the article to a revolving screw-threaded tool while rotating the axis of said tool in a circle ec-' centric to the latter and to the article.- i

It further consists in supporting the article and revolving it while exposing the side of the same to be threaded to the action of'a screw-threaded tool revolving at the same speed as or any even multiple of the speed of the "article and in the same peripheral direction at the point of contact as the art-icle and rotating the axis of such tool in a circle eccentric-to the latter-rand in a direct-ion opposite to that of the revolution of the article.-

' It further consists in other improved steps as will be further set forth.

J This application is a division of an application Serial No. 624,979, filed by me on the 4th day of May, 1911, which issued on the j, fifth dav of December, 1911, as Letters Patent No. 1,010,740, for a machine for threading. sheet metal caps, in which is (118- closed a machine in which my improved method may be carried out.

r The annexed drawings-and the following {description set fox-thin detail one mode of It further consists in fully supporting PatentedJan. 6,1914? talities being hut one form ofmeans for carryin out such method.

In said annexed drawings-Figure rep? resents an axial section of one-half of a carried out. Fig. 2 re'presentsan axial section of the other half of such machine, Fig.

3 represents a top plan View of said latter half of the machine. Figs. 4 and 5 represent axial sections on an enlarged scale of the threading tool and chuck and their sur- .55 machine in which my improved methodis.

rounding parts, *with said -chuck illustrated indisengaged andactuating po'sitions,respec- 1 tively. Fig. 6 represents an elevation of the threading tool and its cooperating parts.

Fig. '7 represents a transverse section of the trunk within which the spindle of'the threading tool is supported." Fig; 8v repre-; sents a diagram illustrating the progress of the threading tool in cutting the thread in the cap. .Fig. 9 re resents an-elevation'of a memberiof the ldham coupling. Fig;

10' represents an elevationof another member of such coupling. C11,};

.' Similar numerals of reference indicate corresponding parts inthe figures;

Referring to the drawings, th'ejreferenoe numeral 1 indicates a bed upon which the several parts of the machine are supported.

A tubular spindle 2, i'sjjohrn'aled in a. hea'r-' of the machinehed and ing, 3, at one en I, in a bushing, 4, sliding'in ahea ingbrackt, 5, upon the bed, and said spindle'is driven by suitableconnection to the 'drive-m'echas nlsm of the machine. 'The bushing is provided with a cross-head, 6, having a transverse groove in its under side-which is engaged by a head, 7, slidable in said groove and swiveled in an eccentric arm upon a veras j tical rock-shaft, 8, connected to .be rocked from the drive-mechanism of the machine at predetermined intervals. Aflchuck, 9, of the dimensions of the article to be threaded,

'iS secured upon the inner end of the spindle, .and a-disk, 10, forms thebottom of the re- 1 cess in said chuck and has a stem, 11, slidable in the axial bore of the tubular spindle and bearing against a rod,,12, which slides iii the spindle and has a spring,-13, forc'1ng it outward. The end of the rod pro ects beyon d the end of the spindle andwill engage v bracket, 15, u'ponthe bed-frame when the spindle is moved outward, and said" rod 12 will thus be held, and byfthecontinued movement ofthe' spindle the rod, stem and disk push. theartiele out of the recess in the chuck. I

The chuck and its" bottom disk; are removable, so that chucks of various sizes and shapesmay be used, aecordingto the size and shape of the article to be threaded. A trunk, 16, is journaled in bearings, 17, upon the machine-bed, with its end opposed to the chuckand inaxial alinement.

with the same and its spindle; Said trunk" has a radial arm,- 18, provided with. a handle, 19, for rocking it, and adjustingscrews, 20, are threaded in'cars, 21, upon one of thebearings and serve to adjust and secure th'eiarm' and trunk in whatever position they may be rocked. The trunk has an eccentric bore, 22, in which a sleeve, 23, is journaled, and said sleeve has all-eccentric bore, 2st, in which a tubular shaft, 25, is journaled. The end ofthe borefan said shaft is formed into a tapering socket, 26, in which the tapering shank, 27, of a screwthreadcd threading-tool, 28, is'secured,-the end, 29, of said tool'beingscrewed intothe end of a rod, 30, which fits in the bore ofjthe shaft and has nuts, 31, and aiwasberf32, upon its projecti' g outer 'eiid,.which bear against the end f the tubular shaft and serve to draw the tapering tool-shank into its socket. A drive-shaft, 33, -revolved from any suitable power-connection,.is journ'aled in bearings, upon the'machin'e bed, one, 34, of said bearings beingillustrated in Fig. )3. Said drive-shaft carries a pinion, 34!, which meshes with-a transmission-pin; ion, 35, which again meshes with a cog? wheel, 36, upon the sleeve in the trunk The drive-shaft carries a cog-wheel 37, which meshes with a pinion, 38, lteye'd .upon a bushing, 39, rotatable upon thesleev in the trunk, and said bushing has a disk, ,4-O, keyed upon it and formed with a'.-di:tmetrical groove, 41, in. its outer face, into which engage two diametrically aline'd tongues, 42, upon the inner face of a disk, 43, having. an

enlargedcentral opening, 44,'t.o admit of eccentric movement. of said .diskhnd this lunularshaft and rod. 'lheouter'face of said disk has two diametrically" ali'ned tongues. at right angles to thdformer tonguesnaml said tongues; engagc'a'diaupon the tubular shaft 25 anthfl lrther se- :upon the periphery ofthe inner disk. The

coupling thus formed, is "the wellknown v ()ldhani coupling iand-r-its operation is well known. A roller or button, 49,- isjouri th rea the inner bearing for the drum. Two rollers,.51, are journaled upon the face of the.

Inner bearing, below the threadingtool,

the chuck may rotate and be supported from.

below'up'on said rollerswhen it is moved inward to have'the threading tool act upon the cap.

Cylindrical hollow articles may be threaded by my improved m'ethod whether such articles have closed or open heads and whether such articles' are flanged, as illustrated in the drawings or have plain sideflanges.

In practice, the article is placed in line with the chuck, as seen in Fig. 4, either manually or by. a feeding device, whereupon the chuck is moved toward the threading tool which will push the blank into the chuck. The outer periphery of the chuck will rest'and revolve upon the chuck-supporting rollers, and, if the article is flanged, as illustrated in the drawings, the small button or roller will bear with its face against such flange and force the same against the face of the chuck. The chuck and the threading "tool rotate in the same direction and with the same rotative speed, or the tool may revolve at a speed of an even multiple of the rotative speed of the e uck, while the axis of the threading tool revolves-in a circle around a center eccentric to the axis of the chuck in a direction of revolution opposite to that of the chuck and at a considerably less speed. .A satisfactory ratio of speeds has been found to be two hundred and forty rotations per'minute for the threading tool and chuck and twenty revolutions per min ute for the axis of the tool.

The rotating threading tool crowds the metal of the rim of the'artiele up between the threads, and as the chuck is rotated, the tool is brought into contact with theentire circumference ofthe article to be threaded,

while the slower revolution of the toolin a eircle'eccentrioto its axis of rotation gradu ally forces the tool-into the metal, crowding. it up between the threadsof the toolto form the; screw-threads. v The outer side of the ar-v ticle remains smooth, as the article fits snugly n the, chuck. so that the threads are not corn'igated. through the thickness .of the- ;melal but are formed upon one sxde, only, by the drawing action of thetnreadmgtool.

- Th. process'of'the formation of the screw- Sl is diagrammatically illustrated in lig.'8,'lv-lterc the wall of the article is indirated-hy-zthe' letten'A, the travel of the threading-tool by a series of circle-segments in variousstyle'sotbroken lines, and the-circular and echentiic path of the axis ofthe thrcading tool by a dotted. circle B. The direetionsI f' movement of the respective parts are indicated by arrows, and the prefcrred number of revolutions per minute by the corresponding numerals. The circumference of the threading tool as it begins to act upon the article is indicated by two fullline circles, C, described by a radius, C at about thirty degrees trom the point where the tool cuts deepest, as indicated by a radius, D, and two dot ed'line circles, D, and the tool leaves the periphery of the article at a'point forty-five degrees (45) from the radius, D, as indicated by a radius, E, and two dotted-line circles, E, described by the latter. As the threading tool and the article rotate in the same direction and at about the same speed, the metal of the article will be drawn or rolled up into the threads of the tool, and the latter will gradually hear deeper into the metal as it rotates and will thereupon be drawn away from the article by its eccentric revolution. The threading tool describes somewhat more than one revolution, substantially even depth, and, at the ratio of speeds above stated, the tool and chuck will make at least twelve rotations to each one revolution of the tool.

By the herein disclosed method, screw-- threads are formed in hollow cylindrical articles upon one side, only,

of the article, without deforming the other side, and Without removing metal from the screw-threaded side' i Other modes of applying the principle of my invention may be employed for the mode herein. employed. Changes may be made as far as instrumentalities and-steps disclosed are concerned, provided the principles of procedure set forth respectively in the fol lowing claims are employed.

Haring thus described my invention what .i claim as new and desire to secure by Letters Patent is i 1. The method of forming screw-threads in cylindrical metal articles, which consists in supporting and rotating such article, applying'a screw-threaded rotating threading .tool to the rotating article, and gradually forcing such tool into theperiphery of such rotating article. v

2. The method of forming screw-threads in cylindrical metal centric to such axis.

of the rotative speed and pheral direction asthe article at the point. of the article,

so that. the thread will be of ,axis.

articles, which consists, in supporting and rotating such article, ap-

forming screw-threads 4. The method of forming screw-threads in cylindrical metal articles, which consists in supporting and rotating such article, applying a screw-threaded threading tool rotating at the same or an even multiple of the rotative speed as the article to the periphery of the same, and revolving the axis of such toolin a .circle eccentric to such axis.

5. The method of forming in cylindrical metal articles, in supporting such article and rotating it, applying a screw-threaded threading tool rotating at the same or an even multiple in the same peri screw-threads which consists of contact to the periphery:

and revolving the axis of such tool in a circle eccentric to such axisin a direction op posite to that of the rotation and at a slower speed.

6. The method of forming in hollow cylindrical metal consists in supporting the entire side of the of the article screw'threads same which is not to be threaded and rotat ing the article, applying a rotating screwthreaded threading tool to the. surface of the article to lie-threaded, and gradually feeding such tool into the metal of the article.

'7. The method of forming screw-threads in hollow cylindrical metal articles, which consists in supporting the entire side of the same which is not to be threaded and rotating the article, applying a rotating screw-- threaded threading tool to the surface o l the article to be threaded, and revolving the axis of such tool in a circle eccentric to such a rotating screw-threaded threading tool to the side to be threaded, and feeding such tool into the metal of the article, thus crowding the metal forming the threads between the threads of the tool.

9. The method of forming screw threalds articles, which 7 The method of forming screw-threads in hollow cylindrical metal articles, which.

consists in fully supporting the side of the article which is not to be threaded and rotate ing such article, applying a screw-threade threading tool rotating, at the sameor an even multiple of tee rotative speed and the same peripheral direction the article at the point of contact to the side of ti article to be threaded, and revolving t. axis of such tool. in a circle cccentric to such axis and in a direction opposite to that of the. article. i V j- 10. The method of. fecal consists in fully supporting the side oitlie ing screw-threads "111 hollow cyllndl'lfitll articles; which article which is not to be threaded and total; l'axis in a directiuu uppositc to that of the lug hlH'll ullitfhf, applying a scrmv-threudm] f ui'livlo and at :1 spvcd slower than hat 0f 1:; flu'umling (no! rotating at U10 same 01' an the latter. Y mm; mulnph of the fulfil 1V0 speed and 111 EUWIX RUST DOUGLAS the same pvl'lphvl'ul (um-011011 as Hm urtlcle, k at- Zlxc point of mum in the side of the \Yiluusmwz' article to be threaded, 2am! revolving Um. .\'Q limx PliUkIUK, k

B. M. EmmNN. 

